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201.
The multi-disciplinary evaluation of a national agri-environment scheme   总被引:8,自引:0,他引:8  
With an increasing amount of public funds being spent on agri-environmental schemes effective methods have to be developed to evaluate them. As many schemes have multiple objectives there is a need for a multi-disciplinary approach to any evaluation. A method was developed to assess the degree to which ecological, landscape, historical and access objectives for the Countryside Stewardship Scheme (CSS) in England have been met. The method used a sample of 484 agreements for which data were collected from surveys, a desk study and an interview with the agreement holder. These data were then evaluated by an expert team of an ecologist, landscape architect, landscape historian, and a social scientist specializing in rural affairs. The team were subsequently brought together with a Chair to discuss their findings for each agreement, allocating scores for each of five criteria: agreement negotiation; appropriateness, environmental effectiveness, compliance and side effects. The additionality that each agreement was likely to provide was also assessed. The results of this process suggest that in the majority of cases the CSS agreements should maintain or enhance the environment in terms of ecology, landscape, and landscape history and increase public enjoyment of the countryside. Thirty-six percent of agreements showed high additionality and 38% medium additionality which demonstrates that the CSS is likely to provide a benefit to society. Agreement negotiation, predicted environmental effectiveness and predicted compliance all improved significantly over the period 1996-98. Recommendations made from this project have been implemented by the Government department to improve the CSS. The multi-disciplinary method was successful and, with further development, could be used for assessment of any agri-environment scheme, or potentially any conservation project or broader 'rural development' scheme encompassing environmental, economic and social objectives. A key to success is the need for the criteria to be tailored for the project concerned and clearly established at the beginning.  相似文献   
202.
Abstract:  The state of Michigan is interested in removing two low‐head dams in an 8.8 km reach of the Kalamazoo River between Plainwell and Otsego, Michigan, while minimizing impacts locally and to downstream reaches. The study was designed to evaluate the erosion, transport, and deposition of sediments over a 37.3‐year period using the channel evolution model CONCEPTS for three simulation scenarios: Dams In (DI), Dams Out (DO), and Design (D). The total mass of sediment emanating from the channel boundary, for the DI case, shows net deposition of 4,100 T/y for the study reach, with net transport (suspended and bed load) of 10,500 T/y passing the downstream boundary. For the DO case, net erosion is 19,200 T/y with net transport of 30,100 T/y (187% increase) passing the downstream boundary. For the D case, net deposition is 2,570 T/y (37% decrease) with transport of 14,200 T/y (35% increase) passing the downstream boundary. The most significant findings were: (1) removal of the low‐head dams will cause significant erosion of sediments stored behind the dams and increased sediment loads passing the downstream boundary and (2) sediment loads for the proposed channel design are similar to existing conditions and offer reduced fine‐sediment loadings.  相似文献   
203.
Book reviews     
Earth Politics. Ernst Ulrich von Weizsacker, 1994, London, Zed Books, 234 pp. ISBN 1 85649 174 9, pb £14.95; hb £36.95

Greening Your Local Authority. Janice Morphet (Ed.), 1994, London, Pitman Publishing (originally Harlow, Longman), 144 pp. ISBN 0582 229 065, pb £32.50

Ecology and Society: an introduction. Luke Martell, 1994 London, Polity Press, 250 pp. ISBN 0 7456 1022 6, hb £39.50, ISBN 0 7456 1023 4, pb £11.95

The Politics of the Environment. Robert E. Goodin, 1994. Cheltenham, Edward Elgar, 599 pp. ISBN 1 85278 872 0, hb £115.00

Introduction to Environmental Impact Assessment John Glasson, Riki Therivel & Andrew Chadwick, 1994, London, UCL Press, 352 pp. ISBN 1 85728 117 9, hb £45.00, ISBN 1 85728 118 7, pb £14.95

Planning for the Planet: sustainable development strategies for local and strategic plans. Friends of the Earth, 1994, London, FoE, 104 pp. ISBN 1 85750 224 8, £12.00

Environmental Strategy and Sustainable Development: the corporate challenge for the 21st century. Richard Welford, 1995, London, Routledge, 240 pp. ISBN 0 415 10551 X, hb £40.00, ISBN 0 415 10552 8, pb £12.99

Housing and the Environment: a new agenda. Mark Bhatti, Jane Brooke & Mike Gibson (Eds), 1994, Foreword by Jonathon Porritt, Coventry, Chartered Institute of Housing, 210 pp. ISBN 0 901 607 738, £14.95  相似文献   
204.
Species diversity and biodiversity are widely used terms in ecology and natural resource management. Despite this, they are not easily defined and different authors apply these terms with varying connotations. The term biodiversity, in particular, has the dubious honour of being widely used but rarely defined. Is it simply the number of species or is it something more? Here I consider what these terms might really mean and their value. I also briefly discuss the rationale for studying and protecting species diversity or biodiversity.  相似文献   
205.
Understanding how human modification of the landscape shapes vertebrate community composition is vital to understanding the current status and future trajectory of wildlife. Using a participatory approach, we deployed the largest camera-trap network in Mesoamerica to date to investigate how anthropogenic disturbance shapes the occupancy and co-occurrence of terrestrial vertebrate species in a tropical biodiversity hotspot: the Osa Peninsula, Costa Rica. We estimated species richness in different categories of land protection with rarefaction analysis and estimated the expected occupancy with a joint species distribution model that included covariates for anthropogenic disturbance, land protection, habitat quality, and habitat availability. Areas with the most stringent land-use protections (e.g., Corcovado National Park, 24 species [95% CI 23–25]) harbored significantly more species than unprotected areas (20 species [19.7–20.3]), mainly due to a reduced presence of large-bodied species of conservation concern in unprotected areas (e.g., jaguar Panthera onca and white-lipped peccary Tayassu pecari). Small-bodied generalist species, such as opossums (Didelphidae) and armadillos (Dasypus novemcinctus), in contrast, were more common at disturbed sites, resulting in a significant difference in vertebrate community composition between sites with low and high disturbance. Co-occurrence of species was also mainly associated with response to disturbance. Similar responses to disturbance create two groups of species, those whose site-level occupancy usually increased as anthropogenic disturbance increased and those whose estimated occupancy decreased. The absence of large-bodied species entails an important loss of ecological function in disturbed areas and can hinder forest development and maintenance. Efforts to protect and restore forested landscapes are likely having a positive effect on the abundance of some threatened species. These efforts, however, must be sustained and expanded to increase connectivity and ensure the long-term viability of the wildlife community.  相似文献   
206.
In some cases, wildlife management objectives directed at multiple species can conflict with one another, creating species trade-offs. For managers to effectively identify trade-offs and avoid their undesirable outcomes, they must understand the agents involved and their corresponding interactions. A literature review of interspecific trade-offs within freshwater and marine ecosystems was conducted to illustrate the scope of potential interspecific trade-offs that may occur. We identified common pitfalls that lead to failed recognition of interspecific trade-offs, including, single-species management and limited consideration of the spatial and temporal scale of ecosystems and their management regimes. We devised a classification framework of common interspecific trade-offs within aquatic systems. The classification can help managers determine whether the conflict is species based through direct relationships (i.e., predator–prey, competition, other antagonistic relationships) or indirect relationships involving intermediate species (i.e., conflict-generating species) or whether the conflict is driven by opposing management objectives for species that would otherwise not interact (i.e., nontarget management effects). Once the nature and scope of trade-offs are understood, existing decision-making tools, such as structured decision-making and real-options analysis, can be incorporated to improve the management of aquatic ecosystems. Article Impact Statement: A synthesis of interspecific trade-offs in aquatic ecosystems supports their identification and resolution.  相似文献   
207.
This study examines the relationship between national-level militarism and consumption-based carbon dioxide emissions. We analyze panel data from 1990 to 2010 for 81 nations to determine whether the magnitude of the effects of (1) military expenditures as percent of total gross domestic product and (2) military personnel as percent of total labor force on carbon emissions change over time. Results of two-way fixed effects models highlight the temporal stability of the environmental impacts of both national-level military characteristics. The findings also reveal that the effect of military expenditures on emissions is larger in the more developed OECD nations than in the developing non-OECD nations. Overall, the results support the treadmill of destruction perspective, which suggests that the nations’ militaries are an important social institution to consider in sustainability science research on the human drivers of global environmental change.  相似文献   
208.
To address the limited application of analytical and modelling techniques in prioritizing revegetation sites for dryland salinity (saline land) management, a case study of the Hodgson Creek catchment in Queensland, Australia, was conducted. An analytical framework was developed, incorporating the use of spatial datasets (Landsat 7 image, DEM, soil map, and salinity map), which were processed using digital image processing techniques and a geographic information system (GIS). Revegetation sites were mapped and their priority determined based on recharge area, land use/cover and sub‐catchment salinity. The analytical framework presented here enhances the systematic use of land information, widens the scope for scenario testing, and improves the testing of alternative revegetation options. The spatial patterns of revegetation sites could provide an additional set of information relevant in the design of revegetation strategies.  相似文献   
209.
Apis florea is a single-combed, open-nesting, dwarf honeybee indigenous to Asia. In common with other species of this genus, A. florea is highly polyandrous, and is therefore predicted to curtail worker reproduction by mutual policing mechanisms that keep worker reproduction at an extremely low level. Policing mechanisms could involve destruction of workers' eggs or offspring, or aggression toward those workers that are reproductively active. We show that in A. florea, worker-laid eggs are eliminated approximately twice as fast as queen-laid eggs, indicating that A. florea uses oophagy of worker-laid eggs as a mechanism of worker policing. Genetic analysis of four colonies indicated that all males produced were sons of queens, not workers. Dissections of 800 workers, from four colonies, did not reveal any significant levels of ovary activation. These results suggest that worker policing is an effective component of the mechanisms that maintain worker sterility in this species. Furthermore, they suggest that worker policing via oophagy of worker-laid eggs is pleisiomorphic for the genus.  相似文献   
210.
Environmental Science and Pollution Research - In the energy-environment literature, a handful of the advanced economies, mostly the European Union countries, have met some of the national...  相似文献   
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